Development and validation of an oral anticoagulant knowledge instrument

Background: Anticoagulants are a high risk class of medication due to their narrow risk-benefit margin. Knowledge regarding anticoagulant medicines is often poor in patients prescribed them, and improving knowledge has been associated with better clinical outcomes. A validated instrument is the generally accepted method of assessing medication knowledge, but no such tools are available for the novel oral anticoagulants which were recently released in Australia. There is need for a validated instrument that can effectively assess anticoagulation knowledge that caters for the novel oral anticoagulants, as well as the older agents.

Aim: This study aims to develop and validate an anticoagulant knowledge instrument to be used in future studies to assess the medication knowledge of patients taking anticoagulant therapy.

Method: The study will begin by a review of existing literature from which a list of relevant questions will be developed. The questions will be reworded for clarity, and content validity will be undertaken in consultation with anticoagulation experts. The instrument will be administered to a total of 200 subjects from a pool of pharmacists, patients, and the general public. The construct validity of the instrument will be assessed using the contrasted group method. The participants will be retested two months after the initial testing to assess test-retest reliability, while internal consistency reliability will be assessed by calculating the Cronbach’s alpha score. Statistical analyses will be conducted using SPSS, 21.0 and Microsoft Excel.

Conclusion: A validated oral anticoagulant knowledge instrument applicable to patients taking warfarin and the novel anticoagulants will reliably identify knowledge gaps in patients. This will assist health care professionals to identify patients at risk and develop strategies to improve the quality use of anticoagulant medications.